In my experience, you will hear nothing, or next to nothing until it is basically fixed. The reason I think is that BMW doesn't want to set false expectations. Say the pumps were shipped out from Germany today, then you may expect a 1 week fix. But what if there was some logistics snafu? They sent the wrong part? Or some staff shortage at the VPC that delayed things?

I recommend that you have your CA keep following up on the status changes as the best remedy. If you feel there is any cause for reimbursement, best to take this up after you get your car. If you think that your case and its handling is the exception rather than the rule, then I recommend that you not get a BMW - I've had my cars in the shop numerous times, and it sometimes takes a week to get the smallest things diagnosed and correctly fixed (never had any money reimbursed). I'd doubt you would get much better results (on average) from Benz or Audi (not sure about Lexus). I don't know if I've ever seen playing the "I won't get another BMW in future" card do much practical good. BMW will usually let someone walk over treating them specially than anyone else. That's my experience from the boards.

In BMW's defense (some of that being excellent service from my dealer), they are apologetic and understanding, and do try and accomodate within their set parameters - like a loaner car. Anything out of those parameters is an unlikely exception.